Exam 3 - dental anatomy Flashcards
what type of teeth do horses have?
what is their eruptation pattern?
hypsodont
continue to reupt thru life of horse: erupt 2-3mm/yr
what are the 2 regions of the crown on a hypsodont tooth?
clinical crown - tooth above the surface of the gum
reserve crown - unerrupted tooth that will become the clinical crown as horse ages
what is the apical surface of the equine tooth?
the surface away from the occlusal surface
what is the lingual surface of the equine tooth?
medial aspect of mandibular teeth
surface next to the tongue
what is the palatal surface of the equine tooth?
medial aspect of maxillary teeth
surface next to the hard palate
what is the buccal surface of the equine tooth?
the surface nearest the cheek
what is the labial surface?
to which teeth does this refer?
the aspect of INCISORS that is in contact w the gingiva of the lips
what is the correct term to describe teeth loc near the front of the oral cavity?
mesial
also describes the most rostral part of each tooth
what is the correct term to describe teeth loc at the back of the oral cavity?
distal
also describes the back each tooth
where is the interproximal space loc?
in between the teeth
what is the diastema?
physiological normal space btwn the canines / corner incisors and first cheek teeth
what is anisognathic?
normal presentation of equine jaw
maxilla is wider than the mandible
what is the clinical significance of the anisognathic nature of the equine jaw?
as a result, the buccal aspect of the maxillary cheek teeth extend beyond the mandibular arcade
why horses develop sharp enamel points on the buccal aspect of maxillary arcades and lingual/palatal surface of mandibular arcades
what is the normal angle of the occlusal surface in horse jaw?
10-15 *
what is the angle of the mandible referred to as?
the Curve of Spee
if the Curve of Spee is sharply angled in a horse, how does that affect the mouth?
mandibular arcades can be angled more forward
t/f
an important aspect of equine dentistry is to alter the angulation of the occlusal surface to improve the horse’s occlusion
false
do NOT alter the angle of occlusion - some angulation is normal and even if it is not good, you are likely to do more harm than good
float points off - do NOT alter occlusal surface
what naming system is used to number horse teeth?
Triadin System
what is the number set appropriate for each quadrant of the mouth?
upper left: 100
upper right: 200
lower right: 300
lower left: 400
which numbers are the incisor teeth?
01, 02, 03
which numbers are the canine teeth?
04
what number is the wolf tooth? [if present]
05
what are numbers of cheek teeth?
06-11
memory cue:
in each arcade, there are ___ upper incisors, lower incisors and cheek teeth
6
what is the MC cause of sinusitis?
dental dz
how many sinuses are a part of the paranasal sinus system?
what is each sinus called?
6
dorsal middle ventral conchan sphenopalatine frontal maxillary
what communicates via the conchofrontal sinus?
dorsal conchal sinus and frontal sinus
which sinus is the largest?
what compartments is it divided into? by what structure?
maxillary sinus
rostral and caudal compartments - divided via the maxillary septum
how does the Cd maxillary sinus communicate w the sphenopalatine sinus?
clinical significance?
via a small opening - loc ventral to the ethmoid turbinates and dorsal to cheek teeth 108/208
an infected 08 tooth can go thru the thin layer of bone an into the sinus easily
the rostral maxillary sinus contains the roots of which teeth?
108/208 and 109/209 - maxillary cheek teeth
the cd maxillary sinus contains the roots of which teeth?
110/111 and 210/211 - maxillary cheek teeth
infections in which teeth might lead to 2* sinusitis?
maxillary cheek teeth: 08, 09, 10, 11
infection of which maxillary cheek teeth should NOT lead to 2* sinus infection?
106/206
107/207
do NOT communicate w sinus structure
what layer of the tissue is the outer layer of the tooth?
cementum
which teeth have infundibulum?
maxillary cheek teeth
what is the infundibulum of the tooth?
invagination of enamel that contains cementum
what layer of tissue is located just deep to the cementum?
this is what is floated off during a dental.
outer enamel [peripheral enamel]
what tissue layer surrounds the infundibulum?
inner enamel
which teeth have 5 pulp horns?
all 07 - 10 teeth
which teeth have 6 pulp horns?
all 06 and mandibular 11s
which teeth have 7-8 pulp horns?
maxillary 11s
why is it important to be cognoscente of which teeth have how many pulp horns and where they are located?
when floating teeth, be careful to NOT get into the pulp horns
how do madibular teeth differ from maxillary teeth?
2 ways
they are simpler than maxillary teeth:
no infundibulum
outer enamel only - NO inner enamel
describe the composition and characteristics of enamel.
what does this mean in term of its function and healing capacity?
- hardest substance in the body, very brittle
- high mineral content and no cellular inclusions => cannot repair itself
where is [peripheral] cementum loc and what is its function?
loc around the peripheral enamel - outer layer of tissue on the tooth
softer than enamel, so Px enamel fracture and helps maintain overall integrity of the tooth
how many types of enamel are there?
3
type 1, 2 and 3
what teeth have type 1 enamel?
fxn?
cheek teeth
fxn to wear resistance, chornic
where is type 2 enamel?
fxn?
incisors
fxn to wear shear forces
where is type 3 enamel?
fxn?
less common distribution
considered a transitional enamel
what tissue makes up the bulk of the tooth?
composition?
fxn?
dentin
made of 70% mineral and 30% organic [collagen, mucopolysaccharides, water]
adds tensile strength and compressibility properties to the tooth
what is the benefit of the laminated structure of the teeth, comprised of dentin and cementum between (btwn) brittle enamel?
- Px cracking of teeth
- creates irregular occlusal surface - rough surface is necessary for grinding forage
how is the differential wear btwn the hard enamel and softer cementum and dentin clinically significant?
soft tissue wears down faster so hard points of enamel are left -> routine care to remove points is necessary to prevent damage to soft pallet
how many types of dentin are there?
3 - 1, 2 and 3*
what are the components of 1* dentin?
fxn?
tubules that surround odontoblast processes
intra tubular dentin tubules: line tubules
intertubular dentin tubules: bridge the pulp to the enamel
what is the structure of 2* dentin?
types?
fxn?
has wider tubules than 1* dentin and has NO intratubular dentin
can be regular or irregular
regular: continuous w 1* dentin
irregular: laid down in response to normal attrition of the occlusal surface of the tooth; Px occlusal pulpar exposure that occurs w wear
tertiary dentin fxn?
laid down locally in response to noxious stimulus - trauma or infection
what is pulp?
composition?
soft tissues w/in dental pulp cavities
contains CT skeleton, vasculature, lymphatics, Nn, fibroblasts
***can differentiate into odontoblasts if stimulated to do so
at the time of eruption, what is a tooth composed of?
a single, large pulp chamber with a thick layer of enamel around the pulp
how does the composition of teeth change by the age of 2y?
by 2 y: both dentin and cementum have been deposited around apical aspects of the tooth
the roots are developing
separate pulp horn development (1y after eruption)
all 07-10 teeth have how many pulp horns?
5
all 06 and mandibular 11 teeth have how many pulp horns?
6
maxillary 11 teeth have how many pulp horns?
7-8
incisor teeth have how many pulp horns?
1
what dental tissue is the softest?
cementum
what is the composition of cementum?
fxn?
white/cream colored, contains 65% mineral and 35% organic compounds and water
- part of the periodontium - ensures the tooth stays anchored in place while it continues to erupt
- improves flexibility over enamel, which is mostly mineral content
- major structural component of the clinical crown - high water and organic content - Px fractures of brittle enamel
- reparative fxn
describe the reparative fxn of cementum?
- peripheral cementum is formed subocclusally throughout the life of the tooth, deposited rapidly in response to stimuli
what do the organic components of the cementum do?
anchor tooth into the bone
where does the blood supply for the tooth come from?
periodontal lig
t/f
incisor teeth are comparable to brachydont teeth in form and fxn
brachydont
how many incisors does an adult horse have?
12
t/f
horses will develop spaces btwn their incisor teeth as they age?
true - incisors taper from the occlusal surface to the apex
what is the infundibulum of the incisor tooth called?
what tissue is it filled with?
the cup
filled w cementum
as the infundibulum wears away, the cup disappears and is referred to as what?
the mark
at what age does the mark on the incisors wear away?
what is left in its place?
18 yrs
dental star - demarcation on the occlusal surface of the incisor
incisors become more or less angulated w age?
more
what is the normal occlusion of the incisors from a frontal view and profile?
front: Horizontal bite plane
profile: Contact edge to edge
what is brachygnathism?
short mandible - maxilla ends up curling over the mandible
many chronic dental issues result - cheek teeth become mal-aligned too
what is an overjet or overbite?
elongated maxilla
what is prognathism?
a protruding jaw
what are some common incisor malocclusions?
slant
irregular incisors
frown
smile
t/f
incisor malocclusions should always be corrected immediately
false
drastic changes made quickly to incisors may do more harm than good
consider leaving them alone if the tops and bottoms occlude reasonably well
if you repair them, do it in a step wise fashion so you do not cause a bigger problem
how to age a horse based on incisors?
eruption times changes in shape changes in occlusal surface Galvayne's groove dental star morphology
which method of aging with incisors is most accurate?
eruption times
what is the eruption time for the first permanent incisors (01) ?
0-2 weeks
avg 6 days
eruption time for 2nd permanent incisor (02) ?
4-6 wks
eruption time for 3rd permanent incisor (03) ?
6-9 mos
when does the permanent premolar 2 (06) erupt?
0-1 week
when does the permanent premolar 3 (07) erupt?
2 wks
how long after eruption does a tooth become “in wear” ?
6 mos after eruption
when does incisor 1 (01) erupt?
when is it “in wear” ?
erupt 2.5 yr
in wear 3 yr
when does incisor 2 (02) erupt?
when is it “in wear”?
erupt 3.5 yr
in wear 4 yr
when does incisor 3 (03) erupt?
when “In wear” ?
erupt: 4.5 yr
in wear: 5 yr
when does the canine (04) erupt?
4-6 yrs
when does PM 1 (05) erupt?
what is the lay term for this tooth?
6-18 mos
“wolf tooth” - some FM do not have it - “vestigial canine” - is often removed
at what age is a horse considered to have a “full mouth” ?
5 yr
which tooth has a tendency to become impacted?
08
at what age does each permanent PM erupt?
PM2 (06) = 2.5 yr
PM3 (07) = 3 yr
PM4 (08) = 4 yr
at what age does each permanent molar erupt?
M1 (09) = 9-12 mos
M2 (10) = 2 yr
M3 (11) = 3.5-4 yrs
how does the upper corner incisor change in shape with time?
at what approximate age of the horse do these changes occur?
5-9 yrs = tooth wider than tall
9-10 yrs = square tooth
> 10 yrs = tooth taller than wide
at what ages does a hook appear on the upper corner incisor?
approximately 7 and 11 yrs
what is the dental star?
what does it look like in young horses and how does it change with age?
what structure does it turn into on the tooth?
2* dentin over the pulp - what used to be the cup
linear shape in young and becomes more oval in shape with age, then more round in shape with age
gradually becomes the mark [around 18 yrs]
what is the dental cup?
an infolding of enamel called the infundibulum
how does the occlusal surface of the incisors change in shape with time/age of the horse?
oval => trapezoid => triangular => oval [opposite orientation from original oval]
how does the angulation btwn the upper and lower incisors change with age of the horse?
angulation increases with age
where does Galvayne’s groove appear?
at what age does it appear? how does its appearance change with age?
loc on upper corner incisor [103/203] on the lingual surface
begins as a shallow, longitudinal groove that gradually elongates and becomes stained darker with plant material
appears at 10 yrs
half way down tooth at 15 yrs
all the way down the tooth at 20 yrs
t/f
canine teeth are the same thing as wolf teeth
false
canines are 04
wolf teeth are 05
are canine teeth MC in M or FM horses?
M
at what age do canines erupt?
5-6 yrs
t/f
canine teeth are commonly removed
why or why not?
false
extremely hard to remove - long and hooked roots make them almost impossible to remove
what Triniadin number is the wolf tooth typically?
05
is the wolf tooth MC loc on the maxila or mandible?
MC loc on the maxilla
t/f
wolf teeth are commonly removed
why or why not?
true
b/c they may interfere with the bit when soft tissue gets pushed against the sharp tooth
may indirectly cause aversion to the bit
what is a blind wolf tooth?
unerupted wolf tooth that can be felt under the surface of the gums
how are wolf teeth typically removed?
standing procedure
sedate and block and elevate - gently
